are you having the same problems with other monitors? this sounds more like an issue with your computer soundcard settings than with the Avantones ..... a speaker is a speaker is a speaker ......

Thanks so much for the reply. The Avantone is my only pro speaker but I don't get the same issue with any other speaker/headphone (e.g. Senheiser HD600).

It sounds as if your cables are wired incorrectly, probably with the speaker signals being taken between L and R instead of the L signal to ground and the R signal to ground, so you are only getting the difference information being sent to the speakers.

You mention that the sound is correct when using headphones, so it's likely you are plugging the Avantones into the stereo headphone jack. You need to check that the L speaker is wired with its XLR pin 2 going to the TRS plug tip and the R speaker wired with its XLR pin 2 going to the TRS plug ring contact. Pins 1 and 3 of both L and R XLRs should be taken to the TRS plug sleeve. An alternative is to use an insert cable connected with the TRS plug going into the headphone output and the send and receive TS plugs into the combo input connectors on the rear of the L and R speakers, respectively.

What audio interface are you using?

Hi Boswell - Thanks so much.

Yes I am plugging the Avantone into the stereo headphone jack. Apologies, I should have said I'm only using one avantone. Also I was incorrect in my first post - I get the same result from using either an XLR or TRS - I just didn't have the TRS plugged in fully and that resulted in me getting a left channel signal from the mixcube speaker.

I have an rme hdspe and also a focusrite i8i6

these are the connection/switches on the speaker I have http://www.avantonepro.com/images/product/1001/full-res/1001-1_full.jpg

If you are using a TRS lead from the headphone jack of the interface going to your single Avantone, either TRS or XLR combo input, then that completely defines your problem. The headphone jack puts out L and R signals on its tip and ring contacts respectively and the differential input of the speaker is wired to receive the difference between those two signals.

If you want to continue taking the signal out of the headphone jack, using an insert cable as I described previously will completely solve the problem. Otherwise, use an XLR-XLR or TRS-TRS lead from one of the rear-panel audio outputs on the interface to your single speaker.

To hear the full content of your tracks, you will need to keep sending mono signals out of your interface until you get a second speaker.

thanks so much I didn't realise that's what the speaker cabinet was doing with the signal!